# Simple Expression Of Product Of Inertia

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Product of inertia of different shapes is related to area moment of inertia. It is also called a ‘product of the second moment of inertia’. Yes, the ‘second moment of inertia’ term is also another name of the area moment of inertia.

People can confuse different inertia terms in engineering. Sometimes people can use wrong inertia calculations in engineering calculations. So, it is very important to know all the inertia terms in engineering correctly.

## What Is Product Of Inertia?

The product of inertia is actually the product of inertias of a shape lying on a plane, with respect to different axes in this plane which are perpendicular to each other.

Product of inertia of a mass or is van be negative, positive, or zero. For example, if one of the axes is the symmetry line of the geometrical area, the product of inertia will be zero.

The exact calculation of the product of inertia is;

The unit of the product of inertia is the fourth power of the length units, which can be millimeters or inches.

## Conclusion

So, it is very basic to calculate the product of inertia. Engineers must not confuse with the mass moment inertia.